(P078) Radiation Therapy in the Management of Carcinosarcoma of the Uterus

Jillian R. Gunther, MD, PhD, Eva N. Christensen, MD, PhD, Pamela K. Allen, PhD, Lois M. Ramondetta, MD, Anuja Jhingran, MD, Nicole D. Fleming, MD, Elizabeth Euscher, MD, Karen H. Lu, Patricia J. Eifel, MD, Ann H. Klopp, MD, PhD; UT MD Anderson Cancer Center; Radiation Oncology Associates

PURPOSE: Uterine mixed Müllerian tumor (MMMT) is often treated with multimodality therapy, including surgery, chemotherapy, vaginal cuff brachytherapy (VCB), and/or pelvic radiation. However, the indications for pelvic and vaginal cuff radiation are unclear. To investigate this, we reviewed our institutional experience with treatment of uterine MMMT.

METHODS: We performed a retrospective review of 155 women with stage I–III uterine carcinosarcoma who underwent total abdominal hysterectomy-bilateral salpingo-oophorectomy (TAH-BSO) at our institution between 1990 and 2011. Overall survival (OS), disease-specific survival (DSS), and pelvic relapse–free survival (PRFS) were calculated using the Kaplan-Meier method, with differences assessed using a log-rank test. Multivariate Cox proportional hazards regression analyses were performed to evaluate the influence of different factors on DSS and PRFS.

RESULTS: The study included patients with stage I (n = 98), II (n = 11), and III (n = 46) uterine MMMT. Median follow-up was 51 months (range: 2–278 mo). A total of 70 patients (45%) received chemotherapy (21 concurrent, 58 adjuvant, 9 both). Also, 108 patients (70%) received radiation therapy (RT); 35% of these patients received pelvic radiation, and 65% received pelvic radiation with or without additional brachytherapy. The 5-year OS for all patients was 48.6% (stage I, 53.8%; II, 30.0%; and III, 42.5%). The 5-year DSS was 57.17% (stage I, 60.88%; II, 44.44%; and III, 51.82%). The first site of recurrence was in the pelvis and/or para-aortic (PA) lymph nodes for 28 patients (44%), abdomen ± pelvis for 13 patients (21%), and distant for 22 patients (35%). On univariate analysis, lower rates of DSS were seen in patients aged ≥ 65 years (P = .001) and with hypertension (P = .03), higher tumor grade (P = .02), cervical involvement (P = .001), and lymphovascular space invasion (LVSI) (P = .004). On multivariate analysis, age ≥ 65 years (P = .001), cervical involvement (P = .03), and LVSI (P = .01) remained independently associated with lower DSS.

PRFS was higher in patients receiving pelvic radiation as compared with VCB or no radiation (88.3% at 5 yr for pelvic radiation vs 67.4% for VCB and 71.2% for no RT; P = .04). Among patients who did not receive pelvic radiation, cervical involvement (hazard ratio [HR] = 3.2; P = .03) and heterologous elements (HR = 2.9; P = .04) were associated with pelvic relapse. In stage III patients, pelvic radiation was associated with higher rates of 5-year PRFS (90.0% vs 55.5%; P = .046), DSS (64.6% vs 46.4%; P = .13) and OS (64.6% vs 34.0%; P = .04). 

CONCLUSIONS: Pelvic radiation reduces the risk of pelvic relapse in patients with MMMT and may be indicated with patients at high risk for pelvic recurrence, including patients with cervical involvement, heterologous elements, and stage III disease.

Proceedings of the 97th Annual Meeting of the American Radium Society- americanradiumsociety.org